Radio adjustment dial



Jan. 12 1926. 1,569,539"

v G. DESJARDINS RADIO ADJUSTMENT DIAL Filed Oct. 13, 1925 4; INVENL 'OR.

ATTORNEYS I Patented Jan. 12, 1926.

UNITED STATES 7 istasse PATENT oFricE.

ennsoitynnsaannrns, or CINCINNATI; orrio, ASSIGNOR T0 oswonrn ELEoTnro Manoraorunme COMPANY a FIRM coivrrosnn one. a. IREDELL, IRA HOLDEN, E. P. BOSWOR'IH, AND enoaea nnsaaanins), or nonwoon, OHIO.

nADIo ADJUSTMENT DIAL.

Application filed October 13, 1925. Serial no. 62,297.

T 0 all whom it may concern:

Be it known that I, GREGORY DESJARDINS, a citizen of the United States, and a resident of Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful improvements in Radio Adjustment Dials, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing, forming part of thi specification.

My invention relates to dials used in the manipulation of the various elements by means of which radio receiving sets or the like are adjusted to give proper tuning or intensity.

There have been a very large number of designs and mechanical constructions provided for the precise purpose just stated, and my invention is directed to the forma tion of a dial or adjustment knob, which embodies in its several structural characteristics those elements in combination whereby a very sensitive and accurate operation can be obtained.

It is well known to all users of radio re ceiving sets that to obtain just the proper fractional movement of an adjustment dial or knob in a radio set is quite difficult, and often the act of removing the hand from the dial will upset the best arrangement, there being only a very small range of adjustment that will serve on some dials, at least, in getting the proper resonance for best reception of any given wave length.

It is my object to provide a knob which in addition to having all of the required mechanical properties, is incidentally so arranged as to be attractive in appearance, although the appearance may be slightly varied without departing from the said mechanical characteristics.

More fully stated it is my object to provide a low central body, preferably rounded so as to avoid interfering with the palm of the hand. At the edges of this body, next to the supporting panel, I form the knob so that the fingers find a concave surface over which to engage. This surface may be provided with gradation marks or calibrations, or else some kind of a pointer or index, and in addition is provided with shallow depressions into which the balls of the finger tips will find a seat, thereby giving a very sensitive touch combined with positiveness of operation.

I accomplish these objects by that certain construction and arrangement of parts to be hereinafter mor specifically pointed out and claimed.

In the drawing:

Figure 1 is a side elevation of my device.

Figure 2 is a plan view thereof.

Figure 3 is a detail section of the device, on the line 3, 3, of Figure 2.

The knob is formed of a suitable body, preferably of a molded solid substance of dielectric properties so as to form a low rounded top 1, extending in a sufficient area to leave a rim which is substantially as wide as the ends of the fingers of an operator manipulating the knob or dial.

The rim 2 is formed in a concave relation, as shown in Figure 1 and Figure 3, and on the rim is mounted an index pointer 3. Instead of the index the rim may be formed with calibrations 3. It is not essential whether the index be on the panel and the calibrations on the dial, or calibrations on the panel andan index on the dial; the latter is, however, the preferable system.

Located about the periphery of the rim are a series of interspaced cavities 4 of rounded form, adapted to fit the balls of the finger tips of anoperator. These cavities are located sufficiently within the outer edge of the knob to leave the calibrations in sufficient length for observation thereof.

I have illustrated by a hand and fingers the proper way of grasping the knob of' my invention, and its mechanical properties as indicated are evident.

Also the arrangement of cavities in the concaved rim, which give the ready and sensiti ve adjustment, together with the low central crown of large area, imparts a striking and satisfactory appearance factor to the device.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1. A radio adjustment knob or dial formed of a piece of material having a cen having indexing means thereon, and interspaced finger tip cavities arranged peripherally thereof, for the purpose described.

2. A radio adjustment knob or dial formed of a piece of material having a central body of large area, with a surrounding dependent rim of concave nature, said rim having indexing means thereon, and interspaced finger tip cavities arranged peripherally thereof, for the purpose described, said central body being formed with a top sufliciently low to clear the palm of the hand Whose fingers engage in the concave rim, With the balls of the finger tips in the cavities.

3. A radio adjustment knob or dial formed of a piece of material having a central body of large area, with a surrounding dependent rim of concave nature, said rim having indexing means thereon, and interspaced finger tip cavities arranged peripherally thereof, for the purpose described, said central body being formed With a top sufficiently low to clear the palm of the hand Whose fingers engage in the concave rim, With the balls of the finger tips in the cavities, said finger tip cavities being of rounded form and symmetrically arranged as in a decorative design.

GREGORY DESJARDINS, 

